Filter cartridge with elastic rings



April 20, 1954 .1. MULLER FILTER CARTRIDGE WITH ELASTIC RINGS Filed May15, 1951 /M W I l INVENTOR JACQUES MULLER I ATTORNEYS Patented Apr. 20,1954 UNITEDv STATES PATENT OFFICE FILTER CARTRIDGE WITH ELASTIC RINGSJacques Muller, La Garenne-Colombes, France Application May 15, 1951,Serial No. 226,438 Claims priority, application France May 16, 1950 3Claims.

This invention relates to filter cartridges of the kind comprising astack of filter discs in which the adjacent odd and even discs areclamped together in pairs successively and alternately at the outer andinner edges, between outer and inner perforated spacing rings. In otherwords, the first disc is clamped against the second disc at the outeredge between two outer rings, the second disc is clamped against thethird disc at the inner edge between two inner rings, and the third discis clamped against the fourth at the outer edge between two outer ringsand so on. This arrangement, known per se, provides a succession ofalternating outer and inner filter cells which communicate respectivelythrough perforations in the spacing rings with a chamber surrounding thecartridge, and with an axial conduit in the cartridge. The outer andinner spacing rings are guided respectively by concentric perforatedtubular casings which are substantially rigid. 7

The object of the invention is to improve the spacing rings in such amanner as to obtain a better clamping of the filter discs, improvedsealing at their outer and inner edges, greater ease of maintenance, andfacility for the rapid assembly of the discs without requiring skilledlabor or special attention.

The invention will be better understood from the following descriptionof a preferred embodiment, illustrated in the accompanying drawings inwhich:

Figure 1 is a vertical axial sectional view through the filter cartridgemounted in a casing;

Figure 2 is a diametric sectional view of an inner spacing ring;

Figure 3 is a similar view of an outer spacing ring; r and Figure 4 is afragmentary diametric sectional View of a pair of spacing rings showinga modification of the shape of the elastic portion of the ring."

The filter cartridge is composed of a stack of annular filter discs I,2, 3, 4, etc. for example of sheet metal, paper, other fiexiblematerial, or any combination of these. The discs are aligned on acentral perforated tube 5 which is preferably rigid. The stack issurrounded by a perforated tubular envelope 6 which preferably is alsorigid. The envelope 6 is centered on the axis of the tube 5 by means oftwo slightly conical rigid annular discs or flanges i, 8 provided at theends of the cartridge and which fit exactly in the annular space. Theirshifting outwardly is prevented by the fact that they bear against theinturned edges of the envelope and the outturned edges of the tube.Thus, as has been stated above, the odd discs I, 3 etc. and the evendiscs 2, 4 etc. are clamped successively and alternately in pairs attheir outer and inner edges between outer and inner spacing rings 9, H),H, [2 etc. The first or lowest outer ring 9 bears against the outer edgeof the flange l. The inner edge of the first or lowest filter disc I isclamped between the flange 1 and the first or lowest inner ring it. Thisfirst disc I is clamped to the second disc 2 at the outer edge betweenthe two consecutive outer rings 9 and i l, the second disc 2 is clampedto the third disc 3 at the inner edge between the consecutiv inner rings10 and [2, the third disc 3 is clamped to the fourth disc A at the outeredge between the outer edge I I, and the following and so on. If theconicity of the fianges l, 8 is made such that the outer rings 9 and l lare spaced axially by one-half pitch relatively to the inner rings [0and I2, it will be seen that there is formed a succession of outer andinner filter cells it, Hi, I5, 16 with the outer and inner cellsalternating with each other. The cells are formed by the filter discshaving a slightly conical shape and being placed alternately with theirconvex and concave faces opposite each other. Through the perforationsin the rings 9, H and in the envelope 6, the outer cells l3, l5communicate with the space surrounding the cartridge. By means of theperforations in the rings l0, l2 and in the tube 5, the inner cells M,It communicate with the central conduit of the cartridge. The latter ismounted in the usual manner between the plate I! and a base It of acover member. Sealing between the outer space and the central channel isprovided by gaskets I9, 20. v

For the spacing of the filter discs, there are employed according to thepresent invention, rings of elastic material of V cross section orpreferably of U cross section, i. e. general channel shaped crosssection, with diverging wings or flanges symmetrical relative to aperpendicular plane passing through the axis of the ring inter' mediateits ends as shown in Figures z'ande, These rings have on the outer faceof their flanges a small peripheral fold or bead 2|, of the shape shownat Figure 2 or similar. The perforations ar formed in the cylindricalwall or in the base of its peripheral groove.

The wings or flanges of the inner rings are directed inwardly and thoseof the outer rings are directed outwardly with variation if necessary.The advantages of this construction are the fol lowing:

The assembly consisting of the stack of filtering discs and spacingrings is compressed in the axial direction for assembly and is held inthis state by the flanges l, 8 which are themselves held at their outeredges at the ends of the envelope 6 and tube 5 by flaring the latter asshown. In the course of the axial compression, the elastic generallyconical wings or flanges of each ring are caused to approach each otherin such manner as to lie in a plane perpendicular to the axis of thecartridge, as shown in Figure 1. However, due to their elasticity theyhave a permanent tendency to separate one from the other and thus tomaintain the clamping of the filter discs without it being necessary toprovide any other means for this purpose. It is necessary to maintain aclose contact between the edges of the discs of each pair to preventdirect passage of the liquid being filtered towards the interior ortowards the exterior of the cells through leaks which might result fromslight irregularities in the rings. The effects of any such irregularities are eliminated due to the elastic deformation of the wings. Thefolds or heads 2! con tribute of the sealing action by penetrating intothe thickness of the filter discs.

It should also be noted that due to the axial compression of thecartridge and the flattening of the conical wings of the spacing rin s,the beads of each of these wings describes the arc of a circle, inwardlyagainst the inner rings and outwardly against the outer rings, andhaving for center the angle of joining with the bottom of the groove ofthe ring. As a result, there is an increase in the diameter of the outerbeads and a decrease in diameter of the inner beads. Referring to Figure1, it is easy to understand the effect produced on the filter discs. Thebeads which may be considered as being hooked to the edges of the filterdiscs, exert on them the traction both towards the interior and towardsthe exterior whereby the discs are stretched. Therefore, it is notnecessary to provide other stretching means nor to insert the filterdiscs between woven or perforated reinforcements adapted to preventtheir excessive bending and their permanent deformation under the actionof the pressure of the filter liquid.

In the form of invention shown in Figure 4, the wings have a greaterradial dimension and have a somewhat corrugated effect which rendersthem more flexible and yet lightly grips the portions of the filterdiscs adjacent their peripheries. In other words, the fianges areprovided with concentric grooves in their surfaces.

It will be understood that without departing from the principles of theinvention, the rings may have a transverse section different from thatshown in the drawing. The essential thing is that each spacing ring,made of elastic material, shall have diverging flattened wings symmetricwith respect to a plane perpendicular to the axis of the ring anddirected outwardly on the outer rings and inwardly on the inner rings sothat any other system of assembly by screw thread means may be providedinstead of the clamping.

I claim:

1. A filter cartridge comprising a stack of substantially conicalalternately inverted filter discs contacting each other in pairs attheir flat outer and inner peripheral margins, perforated spacing ringsof channel shaped cross section made of yielding material insertedbetween the successive pairs of outer contacting margins of the filterdiscs, perforated spacing rings of channel shaped cross section made ofyielding material inserted between the successive pairs of innercontacting margins of the filter discs, each spacing ring having twolateral diverging and yielding flanges symmetrical with respect to aplane at right angles to the axis of the ring and directed towards theexterior of the outer rings and towards the interior of the inner rings.

2. A filter cartridge comprising a stack of substantially conicalalternately inverted filter discs contacting each other in pairs attheir fiat outer and inner peripheral margins, perforated spacing ringsof channel shaped cross section made of yielding material insertedbetween the successive pairs of outer contacting margins of the filterdiscs, perforated spacing rings 'of channel shaped cross section made ofyielding mater'al inserted between the successive pairs of innercontacting margins of the filter discs, each spacing ring having twolateral diverging and yielding flanges with a lateral annular bead onthe outer face thereof and symmetrical with respect to a plane at rightangles to the axis of the ring and directed towards the exterior on theouter rings and towards the interior in the inner rings.

3. A filter cartridge comprising a stack of substantially conicalalternately inverted filter discs contacting each other in pairs attheir fiat outer and inner peripheral margins, perforated spacing ringsof channel shaped cross section made of yielding material insertedbetween the successive pairs of outer contacting margins of the filterdiscs, perforated spacing rings of channel shaped cross section made ofyielding material inserted between the successive pairs of innercontacting margins of the filter discs, each spacing ring having twolateral diverging and yielding, somewhat annularly corrugated flangessymmetrical with respect to a plane at right angles to the axis of thering and directed towards the exterior on the outer rings and towardsthe interior in the inner rings.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,216,646 Mautz Oct. 1, 1940 2,372,865 Taylor Apr. 3, 1945FOREIGN PATENTS Number Country Date 489,860 Great Britain Aug. 4, 1938531,427 Great Britain Jan. 3, 1941 880,629 France Jan. 6, 1943

